This invention relates to a high speed rotating tool and more particularly to a milling cutter using a rotating disk. A band has been included about the disk to restrain expansion caused by centrifugal forces.
Milling cutters are currently designed with a solid body connected to a shank which is attached to a machine tool. Such a design is attractive for most applications with rotational speeds less than 10,000 rpm. In an effort to increase efficiency while at the same time maintaining quality finishes, it is desired to rotate milling cutters at speeds above 10,000 revolutions per minute (rpm). Currently, there is a need to provide a milling cutter which will effectively operate at a speed of at least 30,000 rpm.
Commercially available milling cutters are not capable of such rotation. The cutters are made of steel which has a large specific gravity. The resultant weight of a milling cutter made of steel causes deformation from centrifugal force at high speed operation. This results in misalignment of the cutter inserts and non-uniformity of the dimensions of the machine products.
Furthermore, vibration will still exist during a cutting operation and the ability of vibration attenuation of steel is small. Therefore, this vibration may not be effectively dampened.
Also, a milling cutter of steel has excessive inertia which encumbers a machine tool and requires a longer time for accelerating to or decelerating from a high speed. Acceleration also requires a machine tool having greater power.
U.S. Pat. No. 5,018,915 entitled, "Spindles of Machine Tools" teaches a machine tool spindle comprised of wound carbon or glass fiber impregnated with a heat curable resin for use with the spindle adapted to accommodate the shank of a tool.
Additionally, the article entitled "Energy Storage: Search for the Perfect Flywheel" from Popular Science Magazine, Vol. XX (DATE) teaches the design of high speed flywheels using various composite materials.
Neither of these references teach or suggest a milling cutter design. There exists a need for a milling cutter for use for speeds of at least 30,000 rpm. Additionally, the possibility of tool failure becomes even more important at such high speeds and therefore some mechanism is required to limit the radial expansion of the milling cutter and in the event of failure to physically restrain parts loosened ejected from the milling cutter.
It is an object of this invention to provide a milling cutter of reduced weight to minimize centrifugal forces caused by rotation of the cutter.
Another object of this invention is to provide a milling cutter in which radial expansion is restrained.
Another object of this invention is to provide a means for dampening vibration of the milling cutter body.
Still another object of this invention is to provide a restraining means so in the event of a milling cutter failure any parts that may become loose would be physically restrained from separation away from the milling cutter body.